基于传动可供性评价的机械系统方案设计方法

针对基于功能的设计方法无法将非功能性作用融入机械系统方案设计阶段的问题,提出传动可供性评价的机械系统方案设计方法. 给出传动可供性定义;构建设计需求、传动类型、传动元件、传动可供性的关联关系模型;以设计需求为统一颜色、传动类型为个人颜色、传动件为元素、传动可供性为约束、传动可供性性质为约束统一颜色,建立机械传动系统多色模型. 通过设计需求与传动类型、传动类型与传动件围道推理及合取规则,获得传动类型组合方案粗糙集. 考虑机械传动件约束统一颜色评估为设计准则,以功能可供性信息量最小、非功能可供性理想度最大为综合评价目标,建立传动元件配置优化多目标0-1线性规划模型. 借助跳跃路径二进制位置更新机制和多样性测度维护的布谷鸟算法求解最优传动系统配置方案. 以实例验证该方法的有效性.     

How website socialness leads to website use

Website designers are beginning to incorporate social cues, such as helpfulness and familiarity, into e-commerce sites to facilitate the exchange relationship. Website socialness elicits a social response from users of the site and this response produces enjoyment. Users patronize websites that are exciting, entertaining and stimulating. The purpose of our study is to explore the effects of website socialness perceptions on the formation of users’ beliefs, attitudes and subsequent behavioral intentions. We manipulate website socialness perceptions across two different online shopping contexts, one for functional products and the other for pleasure-oriented products, and draw from the responses of 300 Internet users. Our findings show that website socialness perceptions lead to enjoyment, have a strong influence on user intentions and these effects are invariant across shopping contexts.     

Effect of Inclusion and Filtration on Grain Refinement Efficiency of Aluminum Alloy

Metallurgical and Materials Transactions A - It is well known that the filtration efficiency of ceramic foam filters (CFF) on aluminum melt can be significantly reduced by the addition of grain...     

The Roles of Awareness,Sanctions, and Ethics in Software Compliance

Monitoring agencies continue to express concern over the use of unlicensed business software in organizations because of the ethical, legal, and financial implications of noncompliance. We constructed a multiple mediation model based on protection motivation theory in order to examine the threat and coping evaluation processes of employees regarding software license compliance. The responses of 138 organizational employees were used to empirically test the research model. The research model helps explain why compliance awareness influences compliance attitudes and behavior. The empirical findings indicate that compliance attitudes result from both consequence and coping appraisals with ethical beliefs having a stronger influence on compliance attitudes compared to the threat of sanctions. Furthermore, awareness drives the formation of threat and coping beliefs and directly influences attitude. We discuss the theoretical and practical implications of the findings that will enable organizations to meet the compliance challenge.     

Working to make an image: an analysis of three Philip Morris corporate image media campaigns

Objective

To describe the nature and timing of, and population exposure to, Philip Morris USA''s three explicit corporate image television advertising campaigns and explore the motivations behind each campaign.

Methods

: Analysis of television ratings from the largest 75 media markets in the United States, which measure the reach and frequency of population exposure to advertising; copies of all televised commercials produced by Philip Morris; and tobacco industry documents, which provide insights into the specific goals of each campaign.

Findings

Household exposure to the “Working to Make a Difference: the People of Philip Morris” averaged 5.37 ads/month for 27 months from 1999–2001; the “Tobacco Settlement” campaign averaged 10.05 ads/month for three months in 2000; and “PMUSA” averaged 3.11 ads/month for the last six months in 2003. The percentage of advertising exposure that was purchased in news programming in order to reach opinion leaders increased over the three campaigns from 20%, 39% and 60%, respectively. These public relations campaigns were designed to counter negative images, increase brand recognition, and improve the financial viability of the company.

Conclusions

Only one early media campaign focused on issues other than tobacco, whereas subsequent campaigns have been specifically concerned with tobacco issues, and more targeted to opinion leaders. The size and timing of the advertising buys appeared to be strategically crafted to maximise advertising exposure for these population subgroups during critical threats to Philip Morris''s public image.     

Wettability of Aluminum on Alumina

The wettability of molten aluminum on solid alumina substrate has been investigated by the sessile drop technique in a 10⁻⁸ bar vacuum or under argon atmosphere in the temperature range from 1273 K to 1673 K (1000 °C to 1400 °C). It is shown that the reduction of oxide skin on molten aluminum is slow under normal pressures even with ultralow oxygen potential, but it is enhanced in high vacuum. To describe the wetting behavior of the Al-Al₂O₃ system at lower temperatures, a semiempirical calculation was employed. The calculated contact angle at 973 K (700 °C) is approximately 97 deg, which indicates that aluminum does not wet alumina at aluminum casting temperatures. Thus, a priming height is required for aluminum to infiltrate a filter. Wetting in the Al-Al₂O₃ system increases with temperature.     

Trends in prevalence and acceptance of workplace smoking bans among indoor workers in South Australia

OBJECTIVE: To compare the reported prevalence and acceptance of bans on smoking in the workplaces of a representative sample of adults in South Australia between 1989 and 1994. DESIGN: Independent cross-sectional representative population surveys. SETTING: South Australian population. PARTICIPANTS: Adults who indicated they were employed mainly indoors, for the years 1989 (875 respondents), 1991 (1472), 1992 (1288) and 1994 (1273). MAIN OUTCOME MEASURES: Percentage reporting total bans on smoking at work; percentage reporting compliance with bans all or nearly all the time; percentage reporting preference for total bans at work. RESULTS: The percentage of indoor workers subject to a total ban on smoking at work increased from 32% in 1989 to 62% in 1994 and preference for a total ban increased during the same period from 26% to 52%. Reported compliance with restrictions and bans was very high. In 1994, 16% of workers still had no restrictions on smoking at work, but only 3% preferred this arrangement. CONCLUSION: The data suggest that smoking bans are now the norm for indoor workers and that further gains in promoting and supporting workplace bans will be made by directing efforts at smaller workplaces, where unrestricted smoking is most prevalent.


     

Effectiveness of comprehensive tobacco control programmes in reducing teenage smoking in the USA

OBJECTIVE: To describe the extent to which comprehensive statewide tobacco control programmes in the USA have made progress toward reducing teenage smoking. DATA SOURCES: Literature search of Medline for reviews of effectiveness of programme and policy elements, plus journal articles and personal request for copies of publicly released reports and working papers from evaluation staff in each of the state programmes of California, Massachusetts, Arizona, Oregon, and Florida. STUDY SELECTION: All studies, reports, and commentaries that provided information on aspects of programme implementation and evaluation. DATA SYNTHESIS: Statewide comprehensive programmes show high levels of advertising recall and generally positive improvement in smoking related beliefs and attitudes among teenagers. More fully funded programmes lead to increased mass media campaign advertising and community initiatives; a greater capacity to implement school based smoking prevention programmes; and an increase in the passage of local ordinances that create smoke free indoor environments and reduce cigarette sales to youth. The combination of programme activity and increased tobacco tax reduce cigarette consumption more than expected as a result of price increases alone, and these effects seem to apply to adolescents as well as adults. Programmes are associated with a decline in adult smoking prevalence, with these effects observed to date in California, Massachusetts, and Oregon. Arizona and Florida have yet to examine change in adult prevalence associated with programme exposure. California and Massachusetts have demonstrated relative beneficial effects in teenage smoking prevalence, and Florida has reported promising indications of reduced prevalence. Arizona has yet to report follow up data, and Oregon has found no change in teenage smoking, but has only two years of follow up available. One of the most critical factors in programme success is the extent of programme funding, and consequent level of programme implementation, and the degree to which this is undermined by the tobacco industry and other competitors for funding. CONCLUSIONS: Despite the different strengths and combinations of programme messages and strategies used in these comprehensive programmes, there is evidence that they lead to change in factors that influence teenage smoking, and to reductions in teenage smoking.     

Deep venous thrombosis complicating a congenital absence of the inferior vena cava

BACKGROUND AND PURPOSE: The use of left ventricular assist devices has become an established method in bridging patients with end-stage cardiac failure to heart transplantation. Since thromboembolism is one of the major complications, we undertook this study to evaluate the clinical significance of Doppler microembolic signals (MES) in patients with left ventricular assist devices. METHODS: Six patients with left ventricular assist devices were monitored for MES with transcranial Doppler ultrasonography during the first 30 postoperative days. Additionally, repeated (10 per day and patient) and prolonged (3 hours per patient) monitorings were performed to assess the adequacy of the 30-minute recordings. Three observers evaluated 30 randomly assigned monitorings in a blinded fashion to assess the interobserver variability. The relation between MES counts and clinical, radiological, hemostaseological, and pump flow parameters and the predictive value of MES counts regarding the occurrence of embolic events was evaluated. RESULTS: Ten ischemic cerebrovascular accidents and 2 peripheral thromboembolic events occurred during the observation period of 177 days (total incidence, 6.8%). MES were found in 143 of 170 monitorings (84.1%). Their counts were significantly higher on days with clinically manifest embolic events as compared with event-free days (18.5 [3-74] versus 4 [0-52], respectively, median and 95% CI; P < .001, Mann-Whitney). The predictive value of MES counts above 7 per 30 minutes was high (75%). Significant differences in the incidence and counts of MES as well as in the incidence of clinically manifest embolic events were noted among the six patients (all P < .01) without equal differences in anticoagulant treatment or pump flow. Interobserver agreement was high (p = .78 to .89, unpaired Student's t test). Considerable short- and long-term intrapatient variations of MES counts, without consistent pattern, were noted. CONCLUSIONS: Serial monitoring for MES is prognostically superior to single monitorings in patients with left ventricular assist devices. In the future, this new application mode may individually guide anticoagulation strategies and even influence the decision regarding early cardiac transplantation versus long-term use of the assist devices.